michael101

iTrader: (21)

I apologize for yet another ‘Help me spec my turbo thread’ but I have a few questions and would appreciate any feedback.

I’m about ready to start ordering parts for my DIY Rear Mount setup with FMIC. This setup is for a 99.9% street driven car on drag radials. I ‘think’ that my goal is ~550 to 600 RWHP, if that’s not realistic please point that out.

My car is;
• 2000 Camaro SS
• Stock cubes and compression
• Forged Pistons & Rods with Stock Crank
• EPS 226/234-113+2 .598/.601
• 799 Heads with minor bowl work
• LS6 Intake & 28# Injectors
• Pacesetter Headers, TSP Catted Y
• A4 with Yank SS3600
• 3.73 Gear
• Dyno through the exhaust was 394/380

Here’s what I’m thinking on the system;
• Comp Oil-less turbo
• 2.5” Al. cold piping to FMIC
• 31x12x4” FMIC
• BOV (not sure what size)
• Wastegate (not sure what size)
• 60# injectors (just guessing)
• New fuel pump setup

Questions:
1. At this point I have one recommendation on the Comp Turbo. That is for a CT43 6765 Billet 3 Ceramic BB and .81 a/r. Any feedback or opinions on that would be appreciated.
2. Is the 2.5” piping the right size?
3. Is my choice of FMIC correct?
4. What size and brand BOV and Wastegate should I be looking at?
5. Thoughts on injector and fuel pump sizing.
6. Will my cam work ok with turbo?

Adam86

iTrader: (10)

1. Don't know much about those turbos. A/R seems good. Does the 6765 signify that it is a 67mm turbo?
2. 2.5" should be good at that power level. Any bigger and you'll have some rough lag.
3. I would personally go with something smaller at your planned power level. The intake charge on rear mounts seems to be naturally a little cooler due to the length of the charge piping. I would say a 3" thick IC will be more than fine. If your IATs are still higher than you want, get a meth system.
4. I went with a Tial BOV, they have a good following. You could maybe cheap out on a Chinese one and see what happens since it's not a part that will blow your motor if it fails. But DO NOT cheap out of the wastegate! Turbosmart, Tial, etc... stick with something brand name there. If it fails you can easily kill your motor. A 38 or 44mm unit should be fine.
5. I wouldn't screw around on the pumps. Just go with the dual 255s with one on a Hobbs and call it a day. Will leave you lots of room to grow. As for injectors, HI 60lbers should do the trick at that level.
6. Don't know jack **** about FI cams. If you know everything there is to know about what cam to run with what FI setup you could probably fill a good sized book. Went with a Z06 cam myself to save the headache of specing one out.

Adam86

iTrader: (10)

Also, I would maybe look into some 317 heads since you have stock compression now. I have 243s but am running dished pistons and I'm assuming you have flat tops.

michael101

iTrader: (21)

Thanks Adam

The Comp catalog is showing that the part number CT43-6765 has a HE 65 turbine wheel with a 4" inlet and 3" outlet. I'm not that familiar with Comp either.

michael101

iTrader: (21)

Adam86

iTrader: (10)

I think that turbo may end up being a touch small. May want to consider a 70mm

michael101

iTrader: (21)

I keep going back and forth on the Comp Oil-less turbo vs. using a T-netics or similar. I REALLY like the idea of not using the engines oil to cool the turbo. I know that there are lots of folks running the oiled turbo with a scavenger pump and doing just fine.

The Comp turbo is pricey ~$1900. I'm having trouble pulling the trigger on that. But I probably wont be that far off on money if I go with a typical turbo plus the scavenger pump and lines right? I'm thinking $1200 for a turbo plus $350 for the pump set up.

dschmittie1

iTrader: (64)

Your not using engine oil to cool the turbo you are using it to lubricate the bearing.


Also your cam may work but it is far from ideal. reverse splits are better spooling turbos. Also you will probably want to ditch the headers and put stock manifolds back on the car. also plan on wrapping the exhaust all the way back to the turbo. The headers will cause to turbo to spool slow. Stock manifolds and wrapped exhaust will make it spool faster.

b00sted

iTrader: (7)

My buddy did a rear-mounted 78mm precision and had nothing but problems with oiling...Even after buying a badass Weldon return pump.

If the comp oiless turbos work as well as people say they do, I'd go that route. I think you still need to run water/coolant to them though? That wouldn't be an issue though since you can keep the water pressurized and not worry about blowing out a seal or anything.

michael101

iTrader: (21)

Yep. I'm not saying that the scavenger pump is a bad idea, it is obviously working for a lot of people. But I just don't think it's right for me. I'm way more comfortable with the oil-less idea.

There's not much out there on the performance and durability of the comp turbo yet.

It's going to take me a while to get the whole system built anyway so I have time to watch and research more. For now I'm going to start on the parts that I need to install regardless of which turbo I end up going with.